The kinetic data and chemistry of asphalt oxidative age hardening suggested a sequential, dual mechanism for asphalt oxidation. The dual mechanism rationalizes conflicts between earlier mechanistic investigations and explains the hyperbolic-like, time-versus-property plots characteristic of asphalt oxidative aging. The oxidation kinetics provide further confirmation of the asphalt microstructural model. It is proposed that the rapid initial oxidation rate of asphalt results from reaction of oxygen with limited amounts of highly reactive hydrocarbons. Final oxidation products of this initial reaction are sulfoxides and, most likely, ring aromatization. During this initial reaction, a slower oxidation reaction of asphalt benzylic carbons is initiated; final products are ketones and sulfoxides. The ratio of ketones to sulfoxides formed and the rate of age hardening were found to be dependent on temperature and oxygen pressure. Low-temperature oxidative aging, as occurs in pavements, was found significantly more sensitive to variations in temperature and asphalt composition than 100°C pressure vessel aging.


    Access

    Download

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Asphalt Aging: Dual Oxidation Mechanism and Its Interrelationships with Asphalt Composition and Oxidative Age Hardening


    Additional title:

    Transportation Research Record: Journal of the Transportation Research Board


    Contributors:


    Publication date :

    1998-01-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English





    Oxidative Aging of Asphalt Binders in Hot-Mix Asphalt Mixtures

    Morian, Nathan / Hajj, Elie Y. / Glover, Charles J. et al. | Transportation Research Record | 2011


    Interrelationships Among Stiffnesses of Asphalt Aggregate Mixtures

    Kim, Y. R. / Lee, Y.-C. | British Library Online Contents | 1995


    Effect of Oxidation Pressure on Asphalt Hardening Susceptibility

    Domke, Christopher H. / Davison, Richard R. / Glover, Charles J. | Transportation Research Record | 1999